The native of Brownsburg, Indiana, will have to sit out the 2018 season but will have three years of eligibility remaining starting in 2019.

A true freshman in 2017, Johnson completed 21 of 27 passes for 234 yards with two touchdowns and one interception for Clemson, spending the season behind Kelly Bryant and Zerrick Cooper on the team's depth chart. He enrolled early last January as the nation's top-ranked pocket passer and competed for the starting job through spring and fall camps.

Clemson quarterback Hunter Johnson (15) runs in for a touchdown during the the spring game in Memorial Stadium in Clemson on Saturday, April 14, 2018.(Photo: Ken Ruinard/staff)

Johnson announced his decision to transfer on May 21, after it became clear he was behind Bryant and true freshman Trevor Lawrence in the race for the starting gig. He had reportedly narrowed his transfer options to Northwestern and Purdue.

"I'm thrilled to be part of the Wildcat family," Johnson said through the school. "The program that Coach (Pat) Fitzgerald and his staff have built at Northwestern is phenomenal, and one my family has had the opportunity to get to know and trust.

"I am thankful to Coach Swinney and the Clemson family for all their support over the past year-and-a-half. My focus now is doing everything in my power to help this team compete for a BigTen West title."

Johnson was the latest in a line of several notable players to transfer from Clemson this offseason, including fellow quarterbacks Zerrick Cooper and Tucker Israel, and defensive tackle Josh Belk.